How to distribute objects in a circular pattern on a surface (Radial Array, Polar Array)
Radial / Polar / Circle Array

First decide how many rings of holes you want, and the sizes of these various holes. The inner ring usually has a different hole count than the outer larger ring.

For the sake of demonstration let's say I pick 3 different sizes

hole count per ring | angle between each hole
--------------------+----------------
big hole: 20        | 360 / 20
smaller hole: 15    | 360 / 15
smallest hole: 10   | 360 / 10


A convenient way, which doesn't appear to be obvious for a lot of people, is to use the Array Modifier and a rotated Empty. The rotated empty will be used as the centre of the radial array. The rotation of the empty will control the angle of rotation of the arrayed objects.

If you want a radial array of 15 objects (for educational purposes I will array around the world center (0,0,0), and the plane is X,Y :


you place an Empty at (0,0,0), rotate it around z by 360/15

add a circle to the world at (0,0,0) and in edit mode move the vertices to in the X direction to until you are happy with where it is


Pick your Object, add Array Modifier to the it
set the Object Offset to the rotated Empty




From that point it's up to you what you do, add more rings. In the end you might have something like this, i've zoomed into the Empties to show that it might look a bit cluttered and that's to be expected (this is why naming your Empties is very important)